Mount Prospect, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

363
FXUS63 KLOT 111129
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
629 AM CDT Wed Mar 11 2026

.KEY MESSAGES...

- Periods of rain today, possibly mixing with light snow across
  northern IL.

- Very strong winds (gusting 45+ mph) Thursday night/Friday.

- Storm system Sunday with rain/snow or accumulating snow north
  and possibly thunderstorms (some strong?) across the south.

- Turning much colder early next week with Monday morning and
  Tuesday morning wind chills possibly below zero.

&&

.DISCUSSION...
Issued at 255 AM CDT Wed Mar 11 2026

Low pressure will move northeast of the area this morning with
a trailing cold front moving south of the cwa, which will end
the threat of any strong/severe thunderstorms, though isolated
lightning may still be possible through mid morning. Periods of
rain are expected through early/mid afternoon and as colder air
continues to spread into the region, this rain may mix with or
change to light snow across northern IL, though no accumulation
is currently expected. Northwest winds are expected to gust into
the 30 mph range today, especially this afternoon and then
winds will diminish this evening as a ridge of high pressure
quickly moves across the area.

Attention then turns to a period of very strong winds expected
Thursday night into Friday. Low pressure will deepen over the
northern Plains Thursday into Thursday night and continue to
deepen as it moves across the northern Great Lakes region
Friday. The low also may slow its forward speed as it crosses
the lakes. Southerly winds will begin to increase Thursday
afternoon and continue increasing Thursday evening when gusts
into the 45+ mph range will be possible. Winds will shift
westerly behind a strong cold front Friday morning. There may be
a period of gusts in the 50+ mph range with and just behind the
front and then winds will slowly diminish into Friday
afternoon. If these wind trends continue, a wind advisory may
eventually be needed with later forecasts and its possible that
if higher wind gusts are expected, there may be a need for a
high wind watch. Too early for either with this forecast.

Another fast moving ridge crosses the area early Saturday
morning and there has been a signal for several days for a
narrow warm air advection band of snow or a rain snow mix
Saturday morning, perhaps only affecting the northwest or far
northern cwa. Blended guidance chance pops seem reasonable for
this potential for now.

A storm system is then expected to move across the area on
Sunday. There remains quite a bit of uncertainty with this
system though the GFS remains consistent with a bit more
southern track and perhaps more snow for the local area vs. the
ECMWF which is a bit further north and less snow for the local
area. If the warm sector expands far enough into the cwa, there
is enough instability that thunderstorms, perhaps strong or
locally severe would be possible. At the same time, much colder
air is spreading into the region on the back side of this
system, with precipitation likely to change over to snow,
perhaps with a wintry mix during the transition Sunday afternoon
into Sunday evening. The storm system is expected to deepen as
it departs with strong/gusty northwest winds likely Sunday night
into Monday. With low temps by Monday morning possibly in the
teens, these winds would push wind chills below zero for parts
of the area Monday morning. Winds will be lighter by Tuesday
morning, but with air temps possibly in the single digits across
the north, wind chills Tuesday morning may also be below zero
for parts of the area. Temps begin to moderate by the middle of
next week. cms

&&

.AVIATION /12Z TAFS THROUGH 18Z THURSDAY/...
Issued at 629 AM CDT Wed Mar 11 2026

Forecast concerns include...

Ifr/Lifr cigs through this afternoon.
Periods of rain through this afternoon.
Chance of snow late morning into this afternoon.
Gusty north/northwest winds through sunset.

Periods of rain are expected today with a lull possible mid
morning. Previous model runs were suggesting another period of
rain late morning into the early afternoon, but most recent
guidance is trending away from this so confidence is lower for
additional rain later this morning into the afternoon. If this
precipitation does develop, with colder air spreading into the
region, the rain may mix with snow at times, possibly changing
to snow across far northern IL. Current prob mention has this
potential handled for now, but trends will need to be monitored.
All precipitation should be ending by late afternoon with dry
conditions expected tonight into Thursday morning.

Lifr/ifr cigs are expected through early afternoon, eventually
lifting to low mvfr this afternoon and scattering out this
evening, from west to east.

Northerly winds to start this morning will slowly turn to the
north/northwest this morning with speeds/gusts slowly
increasing. Gusts into the mid/upper 20kt range are expected
from mid morning through sunset. Winds will diminish this
evening and turn more westerly overnight. cms

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 4 AM CDT Thursday for Winthrop
     Harbor to Northerly Is. IL.

     Small Craft Advisory from 10 AM this morning to 4 AM CDT
     Thursday for Northerly Is. to Gary IN.

     Small Craft Advisory from 10 AM this morning to 10 AM CDT
     Thursday for Gary to Burns Harbor IN-Burns Harbor to
     Michigan City IN.

&&

$$

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